Determine if the supplied chain iterator is at the begining of a legal date and/or time. If it is then the supplied hzXDate reference is populated. The lenth of the date/time sequence is returned so that the calling process can choose to advance the iterator by this length. The iterator is not advanced by this function Expects dates of the form "day_name, dd month_name yyyy hh:mm:ss Time-Zone"

Declared in file: hzTextproc.h
Defined in file : hzDate.cpp

Function Logic:

Function body:

uint32_t IsFormalDate (hzXDate& date)hzChain::Iter& ci, 
{
   //  Category: Text Processing
   //  
   //  Determine if the supplied chain iterator is at the begining of a legal date and/or time. If it is then the supplied hzXDate reference is populated. The
   //  lenth of the date/time sequence is returned so that the calling process can choose to advance the iterator by this length. The iterator is not advanced
   //  by this function
   //  
   //  Expects dates of the form "day_name, dd month_name yyyy hh:mm:ss Time-Zone"
   //  
   //  Arguments: 1) date The full date
   //     2) ci  Chain iterator to be tested
   //  
   //  Returns: Number being length of the date string if found
   chIter      zi ;                //  Internal chain iterator
   hzTimezone  tz ;                //  Timezone
   uint32_t    n ;                 //  Counter
   uint32_t    dow = NULL_DOW ;    //  Day of week
   uint32_t    len = 0;            //  Length of examined text
   uint32_t    Y = 0;              //  Year
   uint32_t    M = 0;              //  Month
   uint32_t    D = 0;              //  Day
   uint32_t    h = 0;              //  Hour
   uint32_t    m = 0;              //  Minute
   uint32_t    s = 0;              //  Second
   uint32_t    hOset = 0;          //  Hours in timezone offset to GMT
   uint32_t    mOset = 0;          //  Minutes in timezone offset to GMT
   char        numBuf[4];          //  For reading numbers
   zi = ci ;
   tz.clear() ;
   for (; !zi.eof() ;)
   {
       if (*zi < CHAR_SPACE)
           break ;
       if (*zi == CHAR_SPACE || *zi == CHAR_COMMA || *zi == CHAR_PAROPEN || *zi == CHAR_PARCLOSE)
           { len++ ; zi++ ; continue ; }
       if (IsDigit(*zi))
       {
           //  We are looking for a day of the month, a year or the start of a time sequence
           n = IsTime(h, m, s, zi) ;
           if (n)
               zi += n ;
           else
           {
               for (n = 0; IsDigit(*zi) ; zi++)
                   { n *= 10;n += (*zi - ''0'');}
               if      (n < 32&&D == 0)    D = n ;
               else if (n < 10000&&Y==0)Y= n ;
               else
                   return 0;
           }
       }
       if (IsAlpha(*zi))
       {
           //  We are looking for a day name, a month name or a timezone code
           if (dow == NULL_DOW)
           {
               for (n = 0; n < 7; n++)
                   if (zi == hz_daynames_full[n])
                       { dow = n ; break ; }
               if (dow == NULL_DOW)
               {
                   for (n = 0; n < 7; n++)
                       if (zi == hz_daynames_abrv[n])
                           { dow = n ; break ; }
               }
               if (dow != 8)
                   { for (; IsAlpha(*zi) ; zi++) ; continue ; }
           }
           if (M == 0)
           {
               for (n = 0; n < 12;n++)
                   if (zi == hz_monthnames_full[n])
                       { M = n + 1; break ; }
               if (M == 0)
               {
                   for (n = 0; n < 12;n++)
                       if (zi == hz_monthnames_abrv[n])
                           { M = n + 1; break ; }
               }
               if (M >&eq; 0)
                   { for (; IsAlpha(*zi) ; zi++) ; continue ; }
           }
           if (!tz.code)
           {
               for (n = 0;; n++)
               {
                   if (zi == _hzGlobal_Timezones[n].code)
                       { tz = _hzGlobal_Timezones[n] ; break ; }
               }
               if (tz.code)
                   { for (; IsAlpha(*zi) ; zi++) ; continue ; }
           }
           return 0;
       }
       if (*zi == CHAR_PLUS || *zi == CHAR_MINUS)
       {
           //  We are looking for a timezone offset to GMT (of the form +/-dddd)
           zi++ ;  numBuf[0]= *zi ;
           zi++ ;  numBuf[1]= *zi ;
           zi++ ;  numBuf[2]= *zi ;
           zi++ ;  numBuf[3]= *zi ;
           if (IsDigit(numBuf[0])&& IsDigit(numBuf[1])&& IsDigit(numBuf[2])&& IsDigit(numBuf[3]))
           {
               hOset = ((numBuf[0]- ''0'')*10)+(numBuf[1]- ''0'');
               mOset = ((numBuf[2]- ''0'')*10)+(numBuf[3]- ''0'');
               if (hOset > 23||mOset > 59)
                   return 0;
               zi++ ;
               continue ;
           }
           return 0;
       }
   }
   if (date.SetDate(Y, M, D) != E_OK)  return 0;
   if (date.SetTime(h, m, s) != E_OK)  return 0;
   ci = zi ;
   return len ;
}